Devices for cooling and lubricating glass cutting blades by the discharge of a spray of a suitable liquid and air upon such blades when in open or non-cutting position are in wide-spread use. Furthermore, systems have been developed which are designed to be mounted to the shear mechanism and move with the shears or to move with the shears through less than the complete travel of the shears. These mechanisms have experienced serious maintenance problems in that they tend to be complex and, as would be expected, are subject to vibration during their reciprocation. It is difficult to keep proper alignment between the spray and the shears over an extended period of time. Those mechanisms which are positioned to spray only in the open or non-cutting position chiefly use water as the liquid component of the spray, primarily because it is generally available at relatively low cost. Water and air spray heads, however, have some shortcomings, among which may be mentioned the liquid lubricating qualities of water and its tendency to rust metallic parts to which it may be applied. Also to be considered is the presence in water of minerals or other foreign matter which tends to clog and obstruct passages and orifices of the sprayers.
It has been proposed in the past to provide mechanism for combining a substance having good lubricating, cleansing and rust-inhibiting properties with water and air to produce a relatively inexpensive spray for cooling and lubricating the glass cutting blades. One such mechanism is disclosed in U.S. Pat. No. 2,412,268 issued Dec. 10, 1946, wherein a mixture of air and water is directed in a generally fan-shaped configuration at right angles with respect to the longitudinal axis of the shear blades so as to cover two shear blades with the discharge from one spray head. A lubricant such as liquid detergent is mixed or injected cyclically into the water in response to each cutting cycle of the shear mechanism. This ability to inject a cleansing, lubricating and rust-inhibiting material into the stream of water is disclosed as being an improvement over the mode of operation of a shear spray mechanism of the type disclosed in U.S. Pat. No. 2,230,609 dated Feb. 4, 1941.
With the foregoing in view, it is an object of the present invention to provide a more stable mechanism for spraying shear blades in which closer control both as to the amount and application technique is accomplished in a shear spray process where the spray is continuously in operation.